A Philadelphia man has been jailed for 2½ years for smuggling African elephant ivory into the United States, in a case that resulted in one of the largest seizures of illegal ivory in US history.

Victor Gordon, 71, was also ordered by US District Judge Kiyo Matsumoto in Brooklyn to pay a US$7500 (NZ$8912) fine and forfeit US$150,000, along with roughly one ton of elephant ivory that federal agents collected from his art store in April 2009.

The sentencing caps an eight-year investigation that has resulted in nine convictions in Brooklyn for illegally importing elephant ivory, prosecutors said.

The slaughter of African elephants for their ivory remains a major threat to their survival, according to conservationists, and the illegal trade has gained attention in the United States in recent years.

Brooklyn US Attorney Loretta Lynch said in a statement that the prosecution of Gordon was emblematic of the United States' commitment to prevent the flow of illegal ivory within its borders.

"The illicit trade in elephant ivory has created an environmental crisis in Africa and is fuelling the development of organised criminal groups around the world," Lynch said.

Prosecutors said Gordon acquired over a nine year period more than 400 pieces of carved elephant ivory worth US$800,000.

Daniel-Paul Alva, Gordon's lawyer, did not respond to a request for comment. In court papers, Alva had asked that Gordon receive no jail time. He also said that while Gordon collected ivory, it was not the central part of his business or life, and he was not the "criminal mastermind" portrayed by prosecutors.